Diagonal clamshell protective enclosure

ABSTRACT

A bifurcated pipeline gas sample takeoff equipment housing having a diagonally oriented access opening to increase the ease of access to enclosed components by increasing the opening size by up to thirty percent without increasing the size of the enclosure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is an application filed under 35 U.S.C. §111(a) claiming benefit pursuant to 35 U.S.C. §119(e)(1) of application Ser. No. 29/376,712, filed on Oct. 11, 2010, pursuant to 35 U.S.C. §111(b), the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to enclosures for outdoor pipeline sampling instrumentation. More particularly, the invention relates to an improved diagonal clamshell-type, enclosure structure that protects the enclosed instrumentation devices and maintains the interior enclosure temperature within a select range, while providing significantly facilitated access to the enclosed instrumentation.

BACKGROUND OF THE INVENTION

Maintenance of sampling and analysis instrumentation and equipment for gas pipelines including LNG pipeline networks, is important for the efficient and accurate delivery of the piped content. Typically, gas samples are extracted via an apparatus mounted near or on a gas pipeline by using a so-called insertion probe. Once the gas sample is extracted, it is provided through stainless steel tubing to a sample tank or, in more sophisticated systems such as those illustrated in Applicant's U.S. Pat. Nos. 7,162,933 and 7,882,729, directly to an analyzer such as a chromatograph. In delivering the gas to either, it is important to maintain the heterogeneity of the gas mixture while maintaining the sample at a temperature to prevent hydrocarbon dew point dropout, i.e., condensation which results from a failure to maintain the gas sample temperature above its dew point to prevent hydrocarbon drop-out.

In the case of natural gas, typically, the sample takeoff is located on the pipeline usually in an inhospitable ambient environment, e.g., where outdoor ambient temperatures differ significantly from the gas dew point dropout temperature. Accordingly, as taught in the above-referenced patents, a heating mechanism is employed so as to maintain the gas at a temperature adequate to prevent dropout. Although recently, significant technical advances have been made to the sample probe take-off technology, one aspect that has remained relatively static from a technology perspective is the protective housing for sampling and analysis take-off equipment mounted directly to a pipeline.

Typically, such conventional protective housings adequately encase the pipeline mounted equipment. However, access to the content such as the head of the take-off probe is hampered by close spacing of the upwardly standing walls relative to the enclosed equipment. As a result of the confined interior, manipulation is impeded, as is utilization of certain tools. Therefore, unnecessary labor and effort is required for simple adjustment and/or equipment exchange particularly when temporary disassembly of the housing from its pipeline mounting is required. In the case of field repair or inspection, especially in adverse weather conditions, such an impediment is undesirable to the pace and efficiency of maintenance and repairs.

Turning to the present housing structures believed to be most closely related in the field they are illustrated in U.S. Pat. No. 7,162,933 to Thompson et al. which discloses a heated enclosure for a probe directly mounted to a pipeline for gas sampling. Likewise in U.S. Pat. No. 7,484,404 to Thompson et al., a liquid gas vaporization and measurement system incorporating sample take-off housing is depicted. One form of protective enclosure utilized in those patents includes mating upper and lower rectangular halves each featuring a cooperating sealing flange member to provide an environmental seal upon mating. The enclosure is preferably formed from a weather resistant material such as fiberglass and the lower half, the portion mounted on or proximate to the pipe, includes sealable feedthroughs to accommodate components projecting from the underlying pipeline into the enclosure interior, e.g., a sample probe.

Another version of a pipe mounted enclosure for pipeline sample takeoff equipment and sample storage is illustrated in Welker, U.S. Pat. No. 5,531,130. The enclosure includes separable upper and lower halves and maintains the interior temperature to correspond to the pipeline temperature. While serving its protective purpose, the orthogonal orientation of the upper and lower sections limit or interfere with interior access to the feedthroughs as well the floor of the housing interior and components mounted thereon.

Other enclosure types are depicted in Nimberger, U.S. Pat. No. 5,109,709, and Nimberger et al. U.S. Pat. No. 6,539,312, describing hydrocarbon fluid sampling systems directly mounted to a pipeline where the sampling equipment is encased in a protective housing with a hinged door for accessing the housing interior. In Hicks, U.S. Pat. No. 4,553,433 a pipe mounted rotary meter with an integral housing with a hinged instrument cover is disclosed. Neilsen, U.S. Pat. No. 4,630,456 discloses a pipe-mounted, hinged, casket cover and lock for a valve assembly.

While effective for enclosing instrumentation on a pipeline, the art does not address an improved housing structure that would minimize interference to the interior space.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a novel outdoor protective enclosure for gas sampling from a pipeline to which the housing is mounted and which facilitates access to enclosed components by significantly increasing the area of the access opening without increasing the dimensions of the enclosure.

It is another object of this invention to provide a bifurcated, heated gas pipeline probe housing providing minimal obstruction to access of its interior which is demountable on the pipeline that encloses the probe, a heater and valves for sample takeoff.

Further objects of the invention are satisfied by a pipeline mounted housing structure that maintains thermal stability of an extracted gas sample from the source to a remotely situated gas analyzer where the housing permits substantially unobstructed access to enclosed components to facilitated maintenance and repair with increased efficiency.

Still further objects of the invention are satisfied by a pipeline sample takeoff probe housing structure that reduces the discomfort and risk attendant in prolonged exposure to harsh ambient environments by minimizing the time for a person to access components contained within the housing.

To achieve these and other objects an embodiment in accordance with the invention includes a bifurcated clamshell insulated enclosure for housing pipeline sample take-off equipment comprising a lower half section and upper half section matingly interengagable along a diagonally oriented cross-section to establish an insulated enclosure with an opening having an increased area in the range of 20%-30% over that provided by an opening formed by a perpendicular cross-section.

Objects of the invention are also satisfied by a pipeline sampling takeoff equipment enclosure comprising a bottom enclosure section and a top enclosure section said top and bottom enclosure sections being matable to establish the enclosure; said bottom enclosure section including a floor, a pair of spaced apart, upstanding side walls projecting orthogonally from the floor, and front and back walls each defining at least a first and a second collinear, angled, segments where said first segment projects substantially orthogonally from the floor and is substantially longer than said second segment, a continuous, planar, gasketed lip formed by the edges of said first and second side walls and said second segments of said front and back walls; said top enclosure section including a ceiling, a pair of spaced apart, downward side walls projecting orthogonally from the ceiling and front and back walls each defining at least a first and a second collinear, angled, segments where said first segment projects substantially orthogonally from the ceiling and is substantially longer than said second segment, a continuous, planar flange member dimensioned to receive and seat said gasketed lip, said flange member formed at the edges of said first and second side walls and said second segments of said front and back walls; a hooked latch member affixed to each of said side walls of the bottom enclosure section where said latch member is engageable with said flange member of said top enclosure section to compressibly interlock said top and bottom portions and establish the enclosure for the sampling takeoff equipment and a substantially unobstructed front opening to the interior of the bottom section when disengaged.

In brief, the invention provides a novel pipeline sampling takeoff component housing assembly featuring essentially unobstructed frontal access to its interior. In effect, the invention substantially increases the cross-sectional area for access to the housing interior without increasing the size of the three dimensional housing structure. Therefore, access to the housed components, e.g., the sample probe takeoff, a shutoff valve, and a heated pressure regulator for sample gas conditioning,

Indeed, the invention contemplates up to nearly a 30% increase of access area to the housing interior while preserving the integrity of the housing's protective and insulative functionalities. This enhanced access is responsible for increased field work efficiencies particularly for pipeline worker or inspector in hostile conditions.

As used herein “connected” includes physical, whether direct or indirect, permanently affixed or adjustably mounted. Thus, unless specified, “connected” is intended to embrace any operationally functional connection.

As used herein “substantially,” “generally,” and other words of degree are relative modifiers intended to indicate permissible variation from the characteristic so modified. It is not intended to be limited to the absolute value or characteristic which it modifies but rather possessing more of the physical or functional characteristic than its opposite, and preferably, approaching or approximating such a physical or functional characteristic.

In the following description, reference is made to the accompanying drawings which are provided for illustration purposes as representative of specific exemplary embodiments in which the invention may be practiced. The following illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other embodiments may be utilized and that structural changes based on presently known structural and/or functional equivalents may be made without departing from the scope of the invention.

A closely related example of a prior art heated enclosure employed when the probe is remotely spaced from the conditioning and analyzing equipment is of the type described in U.S. Pat. No. 7,162,933 to Thompson et al. This structure minimizes the risk of hydrocarbon dew point dropout following pipeline sample extraction. The significant difference between that prior art enclosure and the present invention is the optimal access to the enclosed components provided by diagonally oriented clamshell bifurcation that maximizes the access opening size without increasing the enclosure size.

Given the following detailed description, it should become apparent to the person having ordinary skill in the art that the invention herein provides a novel pipeline mounted instrumentation housing significantly enhancing accessibility to the housing interior by field workers.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects of the present invention will become more readily apparent by describing in detail illustrative, non-limiting embodiments thereof with reference to the accompanying drawings, in which:

FIG. 1 is a perspective side view of a disassembled embodiment of the invention.

FIG. 2 is a disassembled elevational view of the embodiment of FIG. 1 without probe components and apertures therefor.

FIG. 3 is a top rear perspective view of the assembled embodiment depicted in FIG. 1.

FIG. 4 is side view of the assembled embodiment depicted in FIG. 1.

FIG. 5 is a rear view of the assembled embodiment depicted in FIG. 1.

DETAILED DESCRIPTION OF ILLUSTRATIVE, NON-LIMITING EMBODIMENTS

Exemplary, non-limiting, embodiments of the present invention are discussed in detail below. While specific configurations and dimensions are discussed to provide a clear understanding, it should be understood that the disclosed dimensions and configurations are provided for illustration purposes only. A person skilled in the relevant art will recognize that other dimensions and configurations may be used without departing from the spirit and scope of the invention.

FIG. 1 illustrates a disassembled housing 10 in accordance with the present invention. The housing 10 is formed by a bottom half 12 and a top half 14. (The use of the word “half” is employed as a convenience herein but is not intended to limit the invention strictly to that size. Rather it is intended to approximate the general relative dimensional characteristics of the respective housing portions.) The bottom half has a long rear wall and a short front wall while the top portion has a short rear wall and a long front wall.

From the side (as best viewed in FIG. 4, the housing 10 is irregularly hexagonal with two generally parallel short sides 30 and 32 separated by substantially orthogonally disposed long sides 34. When assembled, the short sides 30 and 32 establish a square of proportions corresponding to the width of the housing. In this manner, the housing 10 defines a generally narrow box like appearance approximating a rectangle but providing a recessed floor area to maintain the lip above the floor of the bottom half 12. If desired, the enclosure 10 may be formed from asymmetrical halves where, for example, the bottom half 12 does not include a short rearward wall and the top half 14 is without either short walls. Such construction however is not preferred because it requires two separate molds and tends to reduce the ruggedness of the enclosure and the size of its interior.

The top and bottom halves 14 and 12 preferably consist of molded/hotpressed glass fiber reinforced polyester and are dimensioned to matingly seal along lower gasketed lip 16 and upper flange 18. Skilled artisans will readily recognize that other durable rigid materials can be used to form the housing but for the purpose of achieving appropriate functionality at the minimal cost, the hot-pressed glass fiber reinforced polyester has been found to be the preferred material. Particularly with reference to FIG. 1, the bottom half 12 seats the upper portion of a pipeline sample probe 20 and an electrical trace heated sample take-off valve 22 for thermal conditioning at the extraction point. A pair of fittings 24 and 26 overlie feedthrough apertures/ports (not illustrated), preferably spaced apart six (6) inches center-to-center and formed in the floor of the bottom half 12. The fittings 24 and 26 respectively secure the sample take off probe 20 and the heated take off valve 22. Preferably, the fitting for the heated valve 22 is positioned so as to seat within the perimeter of the back and side walls of the bottom half 12 thus reducing its exposure to the ambient environment even during repairs while providing easier access.

Each of the side walls of the bottom half 12 include a stainless steel latch 28 preferably riveted thereto proximate to the gasketed lip 16 so as to be able to clampingly engage the flange 18 on the top half 14 when the lip 16 and flange 18 are in confronting, mating engagement. The pivoting latches 28 assist in compressing the mating halves together so that the gasket seals the interior from the exterior environment.

The upper short side walls 30 of each half also incorporates a reinforce platform 36 to which the end of a stainless steel cable tether 38 is secured (as illustrated by a bolt). It should be readily appreciated that the bottom half 12 and the top half 14 could be hingedly affixed at the juncture along the rear wall but to maximize completely unobstructed access, it is preferred that the halves be completely separable. This eliminates the need for hinge mounting of the two halves and permits removal of the upper half 14 from the lower half 12 to access the interior components while retaining the two halves in close proximity when disassembled.

In short, the foregoing diagonal clamshell separable weatherproof housing design facilitates access to its interior to ease labor, time and maintenance issues. This is achieved by substantially increasing the opening to access the enclosed content by up to almost thirty (30) percent without increasing the dimensions of the enclosure itself. This increase is based on fundamental geometry by substituting a diagonally oriented opening for a perpendicularly oriented cross-sectional opening. Without increasing the enclosure dimensions, the area of the opening is effectively enlarged by relying on three dimensions, rather than two dimensions (length and width) of conventional designs.

By way of example, without intending to be limited, upon separation of the top and bottom halves, a conventional 10 inch by 10 inch by 4 inch enclosure defines a 40 square inch opening when bifurcated along the perpendicular whereas a diagonally oriented opening can reach up to over 56.5 square inches or nearly a 30 percent increase. It should be apparent to the skilled artisan that something less than the perfect diagonal can be used to achieve improved access and accordingly, it is intended that embodiments employing sub-diagonal angles but achieving increases exceeding at least about 20 percent fall within the scope of this invention.

Although only a single embodiment of the invention has been disclosed in the forgoing specification, it is understood by those skilled in the art that many other modifications and embodiments of the invention will come to mind to which the invention pertains, having benefit of the teaching presented in the foregoing description and associated drawings. It is therefore understood that the invention is not limited to the specific embodiments disclosed herein, and that many modifications and other embodiments of the invention are intended to be included within the scope of the invention. Moreover, although specific terms are employed herein, they are used only in generic and descriptive sense, and not for the purposes of limiting the description invention. 

1. A bifurcated clamshell insulated enclosure for housing pipeline sample take-off equipment comprising a lower half section and upper half section matingly interengagable along a diagonally oriented cross-section to establish an insulated enclosure with an opening having an increased area in the range of 20%-30% over that provided by an opening formed by a perpendicular cross-section in the same housing.
 2. The bifurcated clamshell insulated enclosure of claim 1 where the clamshell enclosure is formed from two substantially equal sized halves.
 3. The bifurcated clamshell insulated enclosure of claim 2 where the lower and upper half sections include confrontable edges along the diagonal that are enclosure halves are compressibly interengageble.
 4. The bifurcated clamshell insulated enclosure of claim 3 where the confrontable edges of the lower and upper half sections are completely separable and further comprising a tether connected to each of the half sections.
 5. The bifurcated clamshell insulated enclosure of claim 3 further comprising clamps affixed to the lower half section for compressibly engaging the confronting edges upon engagement with the upper half section.
 6. The bifurcated clamshell insulated enclosure of claim 5 where the enclosure is heated by power provided by exteriorly connected heat tracing cable.
 7. The bifurcated clamshell insulated enclosure of claim 5 where the enclosure is mounted directly to a pipeline and houses an pipeline sample probe takeoff, a heated shutoff valve and a heated pressure regulator for heating the gas sample and regulating the pressure of the gas sample to a predetermined pressure value.
 8. A pipeline sampling takeoff equipment enclosure comprising: a bottom enclosure section and a top enclosure section said first and second enclosure sections being matable to establish the enclosure; said bottom enclosure section including a floor, a pair of spaced apart, upstanding side walls projecting orthogonally from the floor and front and back walls each defining at least a first and a second collinear, angled, segments where said first segment projects substantially orthogonally from the floor and is substantially longer than said second segment, a continuous, planar, gasketed lip formed by the edges of said first and second side walls and said second segments of said front and back walls; said top enclosure section including a ceiling, a pair of spaced apart, downward side walls projecting orthogonally from the ceiling and front and back walls each defining at least a first and a second collinear, angled, segments where said first segment projects substantially orthogonally from the ceiling and is substantially longer than said second segment, a continuous, planar flange member dimensioned to receive and seat said gasketed lip, said flange member formed at the edges of said first and second side walls and said second segments of said front and back walls; and a hooked latch member affixed to each of said side walls of the bottom enclosure section where said latch member is engageable with said flange member of said top enclosure section to compressibly interlock said top and bottom portions and establish the enclosure for the sampling takeoff equipment and a substantially unobstructed front opening to the interior of the bottom section when disengaged.
 9. The enclosure of claim 8 further comprising a reinforced section on said second segment of the back walls for securing a retaining cable.
 10. The enclosure of claim 9 where the confrontable edges of the lower and upper half sections are completely separable and further comprising a tether connected to each of the half sections.
 11. The enclosure of claim 10 where the enclosure is heated by power provided by exteriorly connected heat tracing cable.
 12. The enclosure of claim 11 where the enclosure is mounted directly to a pipeline and houses an pipeline sample probe takeoff, a heated shutoff valve and heated a pressure regulator for heating the gas sample and regulating the pressure of the gas sample to a predetermined pressure value. 